Fast reactor nuclear fuel cladding tube, its assembly, and its manufacturing method

Abstract

A nuclear fuel cladding tube for a fast reactor, an assembly thereof, and a method for manufacturing the same are provided. The nuclear fuel cladding tube includes a substrate, a first layer, and a second layer. The substrate has a tubular shape. The first layer is deposited on an outer surface of the substrate. The first layer includes a corrosion-resistant composition. The second layer is disposed on the first layer. The second layer includes silicon carbide fibers infiltrated with silicon carbide. The second layer is configured to inhibit outward creep of the substrate.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63 / 014,820, filed April 24, 2020, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Nuclear fast reactors utilize fast neutrons, rather than thermal neutrons, to generate power, as do light water reactors. Fast reactors typically utilize liquid metal as a coolant that may contact a bundle of nuclear fuel rods. Each fuel rod in the bundle may contain nuclear fuel enclosed within a cladding tube. The cladding tube may provide a barrier to the release of fission products from the nuclear fuel into the coolant during operation of the fast reactor. Controlling degradation of the cladding tube may be a challenge. Summary of the Invention

[0003] The present disclosure provides a nuclear fuel cladding tube for a fast reactor. The nuclear fuel cladding tube comprises a substrate, a first layer, and a second layer. The substrate comprises a tubular shape. The first layer is deposited on an exterior surface of the substrate. The first layer comprises a corrosion resistant composition. The second layer is deposited on the first layer. The second layer comprises silicon carbide fibers infiltrated with silicon carbide. The second layer is configured to inhibit outward creep of the substrate.

[0004] The present disclosure also provides a nuclear fuel cladding tube for a fast reactor, the nuclear fuel cladding tube comprising a substrate and a layer, the substrate having a tubular shape and the layer disposed on the substrate, the layer including silicon carbide fibers infiltrated with silicon carbide, the layer configured to inhibit outward creep of the substrate and inhibit coolant contact with the substrate.

[0005] The present disclosure also provides a method for preparing a nuclear fuel rod for a fast reactor. The method includes depositing a first layer on an outer surface of a substrate to form a coated substrate. The first layer includes a corrosion resistant composition, and the substrate has a tubular shape. Silicon carbide fibers are layered around a mold to create a preform of silicon carbide fibers. The preform is infiltrated with silicon carbide using a liquid preceramic polymer and decomposition of the liquid preceramic polymer into silicon carbide, chemical vapor infiltration, chemical vapor deposition, or a combination thereof to create a second layer having a tubular shape. The second layer is removed from the mold, and the coated substrate is introduced into a cavity defined within the tubular shape of the second layer to form a nuclear fuel rod.

[0006] It is understood that the invention described herein is not limited to the examples summarized in this Summary of the Invention. Various other embodiments are described and illustrated herein. [Brief description of the drawings]

[0007] The features and advantages of the embodiments, as well as the manner in which they are accomplished, will become more apparent and the embodiments will be better understood by referring to the following description of the embodiments taken in conjunction with the accompanying drawings.

[0008] [Figure 1] 1 is a cross-sectional view illustrating an example nuclear fuel rod assembly according to the present disclosure. [Diagram 2] FIG. 1 is a process diagram illustrating an example of a method for making a nuclear fuel rod assembly according to the present disclosure.

[0009] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications described herein illustrate particular embodiments in one form and such exemplifications should not be construed as limiting the scope of the embodiments in any manner. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Certain exemplary embodiments of the present disclosure will now be described to provide a general understanding of the principles of composition, function, manufacture, and use of the compositions, articles, and methods disclosed herein. An example or examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will appreciate that the compositions, articles, and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments, and that the scope of the various embodiments of the present invention is defined only by the claims. Features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention.

[0011] Throughout this specification, references to "various embodiments," "several embodiments," "one embodiment," "an embodiment," or the like mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in the embodiment. Thus, the appearances of "various embodiments," "some embodiments," "in one embodiment," "in one embodiment," and the like throughout this specification do not necessarily all refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in an embodiment or embodiments. Thus, a particular feature, structure, or characteristic that is described or described in connection with one embodiment may be combined in whole or in part with a feature, structure, or characteristic of another embodiment or other embodiments without limitation. Such modifications and variations are intended to be included within the scope of the present embodiments.

[0012] As used herein, particularly in reference to layers, the terms "on," "onto," "over," and variations thereof (e.g., "applied on," "formed on," "deposited on," "provided on," "located on," "electroplated on," etc.) mean applied, formed, deposited, provided, or otherwise located on the surface of the substrate, but not necessarily in contact with the surface of the substrate. For example, a layer "applied on" a substrate does not exclude the presence of another coating layer or other coating layer of the same or different composition located between the applied coating layer and the substrate. Similarly, a second layer "applied on" a first layer does not exclude the presence of another layer or other layer of the same or different composition located between the applied second layer and the applied first layer.

[0013] As used herein, "intermediate" means that the referenced element is disposed between two elements, but not necessarily in contact with those elements. Thus, unless otherwise stated herein, an element "intermediate" between a first element and a second element may or may not be adjacent to or in contact with the first element and / or the second element, and other elements may be disposed between the intermediate element and the first element and / or the second element.

[0014] A fast reactor typically includes a core having a liquid metal coolant (e.g., sodium, lead, lead-bismuth) and a nuclear fuel rod bundle. The liquid metal coolant circulates through the core to extract heat from the nuclear fuel rod bundle. Typically, the nuclear fuel rods of the nuclear fuel rod bundle have a tubular shape. Each nuclear fuel rod may include nuclear fuel and a cladding tube that may provide a barrier to the release of fission products from the nuclear fuel into the coolant circulating in the core of the fast reactor. For example, the nuclear fuel may be sealed within the cavity of the cladding tube such that the nuclear fuel does not physically contact the coolant. As the coolant temperature of the core of the fast reactor increases, the creep strength of the cladding tube typically decreases. In addition, as the nuclear fuel burns during operation of the fast reactor, the nuclear fuel may generate fission gases that may pressurize the cavity in the cladding tube. Therefore, the combination of a decrease in creep strength and an increase in pressure may cause the cladding tube to fail.

[0015] The inventors have found that the cladding forms voids in its structure at high burnups (e.g., greater than 200 megawatt-days per kilogram of uranium (MWd / kgU)), which may be caused by neutron damage associated with high burnup. High burnups are therefore avoided in fast reactors. Furthermore, the cladding may creep outwardly from the nuclear fuel and eventually fail due to void formation between the fuel and the cladding causing an increase in fuel temperature, outward creep of the cladding and / or increased pressure within the cladding causing corrosion of the cladding. In various embodiments, corrosion of stainless steel cladding in lead fast reactors may be accelerated at temperatures of 600 degrees Celsius or higher, and therefore lead fast reactors typically operate at temperatures of 550 degrees Celsius or lower to ensure a margin of safety.

[0016] Thus, the present disclosure provides a nuclear fuel cladding for a fast reactor that may include enhanced corrosion resistance and enhanced creep resistance, such that the cladding may maintain a desirable barrier to fission product release from the nuclear fuel over a variety of fast reactor operating parameters, including elevated temperatures, elevated burnup rates, and elevated primary coolant corrosivity.

[0017] 1, a cross-section of a nuclear fuel rod assembly 100 for a fast reactor is provided. The length of the nuclear fuel rod assembly 100 may be selected to suit the type of reactor desired. For example, the nuclear fuel rod assembly 100 may include lengths ranging from 1 meter (m) to 4 m for a fast reactor.

[0018] The nuclear fuel rod assembly 100 includes nuclear fuel 102 and nuclear fuel cladding 104. The nuclear fuel 102 may include uranium, uranium alloys, uranium compounds, plutonium, plutonium alloys, plutonium compounds, thorium, thorium alloys, thorium compounds, or combinations thereof. The uranium, uranium alloys, or uranium compounds may include uranium-238, uranium-235, uranium-234, or combinations thereof. The thorium, thorium alloys, or thorium compound oxides may include thorium-232. The plutonium, plutonium alloys, or plutonium compounds may include plutonium-239, plutonium-240, plutonium-241, plutonium-242, plutonium-244, or combinations thereof.

[0019] In various embodiments, the nuclear fuel 102 includes or is composed of uranium nitride, which may utilize non-isotopically separated nitrogen (e.g., UN) or isotopically separated nitrogen-15 (e.g., UN15). For example, the UN15 may include a nitrogen-15 enrichment of at least 50% nitrogen-15 based on the total nitrogen atoms in the UN15, such as at least 60% nitrogen-15, at least 70% nitrogen-15, at least 80% nitrogen-15, or at least 90% nitrogen-15 based on the total nitrogen atoms in the UN15. Utilizing uranium nitride may increase the thermal conductivity of the nuclear fuel 102, which may improve reactor performance and minimize or prevent the formation of a eutectic alloy between the nuclear fuel cladding 104 and the nuclear fuel 102. In various embodiments where the nuclear fuel 102 includes UN or UN15, the nuclear fuel 102 may include a thermal conductivity in the range of at least 15 watts / meter / °C and up to 25 watts / meter / °C, depending on the fuel temperature.

[0020] Typically, pure uranium nitride may not be used in light water reactors due to the reactivity between uranium nitride and water. Therefore, uranium nitride is usually alloyed / combined with another material to reduce this reactivity when used in light water reactors. For example, in light water reactors, uranium nitride may contain 10% to 30% zirconium by weight to reduce reaction with water. However, the inventors have found that this reactivity of uranium nitride may not be an issue in fast reactors since water is typically not present and no additives are required. Fast reactor fuel, such as uranium metal, may contain 10% to 30% zirconium by weight to reduce expansion.

[0021] In addition, zirconium in uranium metal fuel for light water reactors can form a eutectic alloy with stainless steel cladding at temperatures above 750 degrees Celsius. Thus, the operating range of uranium metal fuel containing zirconium is typically limited to less than 600 degrees Celsius. However, the inventors have found that pure uranium nitride can be used in fast reactors, so that eutectic alloys can be avoided while maintaining increased uranium density and high fuel thermal conductivity. Increasing uranium density compared to uranium dioxide can also lead to improved operating efficiency of fast reactors. In various embodiments, the nuclear fuel 102 can include more than 90% uranium nitride by weight, such as at least 91% uranium nitride by weight, at least 95% uranium nitride by weight, at least 99% uranium nitride by weight, or at least 99.9% uranium nitride by weight.

[0022] In various embodiments in which the nuclear fuel 102 comprises uranium nitride, the nuclear fuel 102 may have a melting point of greater than 2500 Kelvin, or greater than 3000 Kelvin, etc., depending on the burnup of the uranium nitride. In various embodiments in which the nuclear fuel 102 comprises uranium nitride, the nuclear fuel 102 may have a melting point of 3123 Kelvin. The increased melting point of the nuclear fuel 102 may allow for increased operating temperatures of the coolant in the core of the fast reactor and / or increased safety factors during operation of the fast reactor.

[0023] The nuclear fuel cladding 104 may be separated from the nuclear fuel 102 by a gap 114 (e.g., a void space). The gap 114 may be in the range of 0.05 mm to 2 mm, such as, for example, 0.2 mm to 1 mm, or 0.5 mm to 1 mm. The gap 114 may not be uniform between the nuclear fuel 102 and the nuclear fuel cladding 104, and the nuclear fuel 102 may contact the nuclear fuel cladding 104 at certain locations.

[0024] The nuclear fuel cladding tube 104 may include a tubular shape. In various embodiments, the nuclear fuel cladding tube 104 may include a hexagonal tubular shape as illustrated in Figure 1. In various other embodiments, the nuclear fuel cladding tube 104 may be a different shape, such as, for example, generally cylindrical (not shown).

[0025] The nuclear fuel cladding tube 104 may comprise a substrate 106, an optional first layer 108, and a second layer 110. The substrate 106 may comprise a tubular shape. For example, as illustrated, the substrate 106 comprises a hexagonal tubular shape. The substrate 106 may comprise zirconium, a zirconium alloy, iron, an iron alloy, or a combination thereof. For example, the substrate 106 may comprise a martensitic stainless steel alloy, an austenitic stainless steel alloy, or a nuclear grade zirconium alloy. The nuclear grade zirconium alloy may include Zircalloy-2™, Zircalloy-4™, ZIRLO™, Optimized ZIRLO™, or a combination thereof. For example, the nuclear grade alloy may include a zirconium alloy composition including 0.5%-2.0% niobium, 0.7%-1.5% tin, 0.07%-0.14% iron, max. 0.03% carbon, max. 0.2% oxygen, and the balance zirconium and incidental impurities, all based on the total amount of zirconium alloy. The martensitic stainless steel alloy may include HT-9. The austenitic stainless steel alloy may include 15-15Ti or alumina-forming austenitic (AFA) steels.

[0026] The substrate 106 may have a wall thickness t0 in the range of 0.2 mm to 1 mm, such as, for example, 0.4 mm to 0.7 mm, or 0.5 mm to 0.6 mm. The outer diameter d1 of the substrate 106 may be in the range of 5 mm to 15 mm, such as, for example, 7 mm to 12 mm, such as, for example, 8 mm to 11 mm, or 9 mm to 10 mm.

[0027] The first layer 108 may be deposited on the outer surface 106a of the substrate 106. The first layer 108 may include a corrosion resistant composition. For example, the first layer 108 may be in direct contact with the substrate 106. The corrosion resistant composition may be configured to inhibit oxidation and / or chemical decomposition of the substrate 106 at various operating conditions, including an operating temperature of at least 600 degrees Celsius. For example, the second layer 110 may be porous and allow fluid transport through the second layer 110 such that a fluid (e.g., a coolant in a core of a fast reactor) may contact the first layer 108. The first layer 108 may substantially coat the outer surface 106a of the substrate 106, and the first layer 108 may be substantially impermeable to the fluid. Thus, the first layer 108 may inhibit or prevent the fluid from contacting the substrate 106.

[0028] Additionally, the first layer 108 may be resistant to oxidation and / or chemical decomposition due to contact with the coolant, thereby enhancing the operating range of the nuclear fuel rod assembly 100 in a fast reactor. The first layer 108 may include titanium, a titanium alloy, aluminum, an aluminum alloy, chromium, a chromium alloy, zirconium, a zirconium alloy, a ceramic, or a combination thereof. For example, the corrosion resistant composition may include Ti2AlC, TiAlN, Zr2AlC, chromium, chromium nitride, alumina, or a combination thereof. In various examples, the corrosion resistant composition may include Ti2AlC, TiAlN, Zr2AlC, or a combination thereof.

[0029] The first layer 108 may include a thickness t1 in the range of 0.1 microns to 10 microns, such as, for example, 1 micron to 10 microns, 2 microns to 8 microns, 2 microns to 6 microns, or 3 to 5 microns.

[0030] The second layer 110 may be disposed on the first layer 108, and a gap 112 (e.g., a void space) may be defined intermediate the first layer 108 and the second layer 110. For example, the second layer 110 may be formed in a tubular shape including a cavity 110a, into which the assembly of the substrate 106 and the first layer 108 may be inserted. The gap 112 may allow the substrate 106 and the first layer 108 to expand a predetermined amount before being engaged and / or restrained by the second layer 110. The gap 112 may include a dimension d2 in the range of 50 microns to 2000 microns, such as, for example, 100 microns to 1000 microns, 500 microns to 1000 microns, 400 microns to 900 microns, or 600 to 800 microns. The gap 112 may not be uniform between the second layer 110 and the first layer 108, and the first layer 108 may contact the second layer 110 in certain locations.

[0031] The second layer 110 may be configured to inhibit outward creep of the substrate 106 and the first layer 108 relative to the nuclear fuel 102 and / or to restrain the substrate 106 and the first layer 108. The second layer 110 may include silicon carbide fibers infiltrated with silicon carbide, thereby forming a hard, strong, and / or durable structure to support the shape of the substrate 106. Silicon carbide may retain a desired hardness, strength, and durability over a range of temperatures, including temperatures of at least 600 degrees Celsius. Thus, the second layer 110 may thereby restrain the substrate 106 over a similarly varying temperature range.

[0032] The silicon carbide fibers of the second layer 110 may be infiltrated by a liquid preceramic polymer and decomposition of the liquid preceramic polymer into silicon carbide, chemical vapor infiltration, chemical vapor deposition, or a combination thereof. Chemical vapor infiltration is a process in which a gaseous material is infiltrated into a porous preform at high temperature. For example, chemical vapor infiltration of silicon carbide fibers may include heating silicon carbide fibers in a furnace to high temperature (e.g., at least 1000 degrees Celsius) and introducing a gaseous material into the furnace containing the pores of the silicon carbide fibers. The gaseous material may include a silicon carbide precursor (e.g., trichloromethylsilane) and an optional diluent (e.g., nitrogen). Trichloromethylsilane decomposes into silicon carbide and hydrogen chloride at high temperature. Silicon carbide may be deposited on the silicon carbide fibers, including within the pores and / or on the surfaces of the silicon carbide fibers, and the hydrogen chloride may be removed from the furnace. In various examples, an interlayer may be formed on the silicon carbide fibers prior to introducing the gaseous material. Chemical vapor deposition is similar to chemical vapor deposition, except that silicon carbide is deposited more on the surfaces of the silicon carbide fibers in chemical vapor deposition than within the pores of the silicon carbide fibers.

[0033] In various embodiments, the silicon carbide fibers of the second layer 110 may be infiltrated by a combination of chemical vapor infiltration and chemical vapor deposition to achieve a desired porosity and / or thickness t2 of the second layer 110. The second layer 110 may include a thickness t2 in the range of 30 microns to 500 microns, such as, for example, 40 microns to 500 microns, 50 microns to 500 microns, 50 microns to 200 microns, 80 microns to 200 microns, or 50 to 100 microns. The second layer 110 may include a porosity in the range of 5% to 30% by volume, such as, for example, 5% to 20%, 5% to 15%, 10% to 15%, or 5% to 10%, all on a volume basis. The porosity may allow for a higher degree of heat transport during operation of the nuclear fuel rod assembly 100, as coolant may penetrate the second layer 110.

[0034] In various embodiments, it may be desirable to reduce the permeability of the second layer 110 to prevent permeation therethrough. For example, additional chemical vapor deposition of silicon carbide may be used to form a substantially impermeable tertiary layer 116 on the second layer 110. In various embodiments, the first layer 108 may not be used if the tertiary layer 116 is used. For example, the tertiary layer 116 may inhibit or prevent coolant in the core of the fast reactor from contacting the substrate 106. In addition, silicon carbide may be corrosion resistant. In various other embodiments, another layer (not shown) may be deposited on the opposite side of the second layer 110 in place of or in conjunction with the tertiary layer 116. In various embodiments, the nuclear fuel rod assembly 100 may be configured for use in a light water reactor by inhibiting coolant permeation through the second layer 110. For example, it may be desirable to inhibit steam from penetrating the second layer 110 , which may provide insulating properties to the nuclear fuel rod assembly 100 .

[0035] A nuclear fuel bundle may be created from multiple units of the nuclear fuel rod assemblies 100 by assembling them in a hexagonal or square tight packing relationship. The nuclear fuel bundle may then be placed in a fast reactor. The fast reactor may include a liquid metal coolant, such as, for example, sodium, sodium alloy, lead, lead alloy (e.g., lead alloy with bismuth), or combinations thereof. For example, the fast reactor may be a lead fast reactor utilizing a lead or lead alloy coolant. The lead fast reactor may be operated at a core coolant temperature of at least 600 degrees Celsius utilizing the nuclear fuel rod assemblies 100, such as, for example, at least 700 degrees Celsius, at least 800 degrees Celsius, at least 900 degrees Celsius, at least 1000 degrees Celsius, or at least 1400 degrees Celsius. High temperature operation of the core coolant may be achieved by inhibition of outward creep of the substrate 106 by the second layer 110 and / or corrosion prevention by the first layer 108 and / or the tertiary layer 116. Increasing the operating temperature of the coolant in the core of a fast reactor may increase the efficiency of the energy conversion process in the fast reactor.

[0036] In various embodiments, the fast reactor may operate the nuclear fuel rod assembly 100 at a burnup of at least 300 MWd / kgU, such as at least 350 MWd / kgU or at least 400 MWd / kgU. Increasing the burnup may improve the economic efficiency of the fast reactor.

[0037] Referring to Figure 2, a method for preparing a nuclear fuel rod for a fast reactor is provided. As illustrated, the method can include depositing an optional first layer on an exterior surface of a substrate to form a coated substrate (202). The first layer includes a corrosion resistant composition. The first layer can be deposited by physical vapor deposition, cold spray, thermal spray, or a combination thereof.

[0038] The method may include layering the silicon fibers around a form to create a silicon carbide fiber preform (204). The form may be a tube, mandrel, or similar object. The layering may include stacking, wrapping, braiding, bending, or combinations thereof. The silicon carbide fiber preform may comprise a porosity in the range of 30%-60%, such as, for example, from greater than 30% up to 60%, or 35%-60%, prior to silicon carbide infiltration.

[0039] The silicon carbide fiber preform may be infiltrated with silicon carbide to form a second layer having a tubular shape (206) using a liquid preceramic polymer and decomposition of the liquid preceramic polymer to silicon carbide, chemical vapor infiltration, chemical vapor deposition, or a combination thereof. Infiltration of the preform with silicon carbide may reduce the porosity of the silicon carbide preform and increase the stiffness of the preform. In various embodiments, the process of infiltration may include chemical vapor infiltration followed by chemical vapor deposition. In various embodiments, the process of infiltration may include chemical vapor deposition, chemical vapor infiltration followed by chemical vapor deposition. In various embodiments, chemical vapor deposition is performed on the form prior to layering the silicon fibers around the form.

[0040] The second layer may be removed from the form (208). The coated substrate may be introduced into a cavity defined within the tubular shape of the second layer to form a nuclear fuel rod (210). In various embodiments, a gap may be defined intermediate the first and second layers when the coated substrate is introduced into the cavity. In other embodiments, the nuclear fuel may be inserted and sealed within the substrate.

[0041] Various aspects of the invention according to this disclosure include, but are not limited to, the aspects recited in the following numbered clauses.

[0042] Clause 1. A nuclear fuel cladding tube for a fast reactor, comprising: a substrate having a tubular shape; a first layer deposited on an exterior surface of the substrate, the first layer comprising a corrosion resistant composition; and a second layer deposited on the first layer, the second layer comprising silicon carbide fibers infiltrated with silicon carbide and configured to inhibit outward creep of the substrate.

[0043] Clause 2. The nuclear fuel cladding tube of clause 1, wherein the silicon carbide fibers are infiltrated with silicon carbide by a liquid preceramic polymer and decomposition of the liquid preceramic polymer into silicon carbide, chemical vapor infiltration, chemical vapor deposition, or a combination thereof.

[0044] Clause 3. The nuclear fuel cladding tube of clause 1 or 2, wherein a gap is defined intermediate the first layer and the second layer.

[0045] Clause 4. The nuclear fuel cladding tube of any one of clauses 1-3, wherein the corrosion resistant composition comprises titanium, a titanium alloy, aluminum, an aluminum alloy, chromium, a chromium alloy, zirconium, a zirconium alloy, a ceramic, or a combination thereof.

[0046] Clause 5. The nuclear fuel cladding tube of any one of clauses 1-4, wherein the corrosion resistant composition comprises Ti2AlC, TiAlN, Zr2AlC, chromium, chromium nitride, alumina, or a combination thereof.

[0047] Clause 6. The nuclear fuel cladding tube of any one of clauses 1-5, wherein the substrate comprises zirconium, a zirconium alloy, iron, an iron alloy, or a combination thereof.

[0048] Clause 7. The nuclear fuel cladding tube of any one of clauses 1-6, wherein the substrate comprises a martensitic stainless steel alloy, an austenitic stainless steel alloy, or a nuclear grade zirconium alloy.

[0049] Clause 8. The nuclear fuel cladding tube according to any one of clauses 1 to 7, wherein the second layer has a porosity in the range of 5% to 30% by volume.

[0050] Clause 9. The nuclear fuel cladding tube of any one of clauses 1 to 8, wherein the first layer has a thickness in the range of 0.1 microns to 10 microns.

[0051] Clause 10. The nuclear fuel cladding tube of any one of clauses 1 to 9, wherein the second layer has a thickness in the range of 30 microns to 500 microns.

[0052] Clause 11. A nuclear fuel rod assembly comprising a nuclear fuel cladding tube according to any one of clauses 1 to 10, and a nuclear fuel disposed within the nuclear fuel cladding tube.

[0053] Clause 12. The nuclear fuel rod assembly of clause 11, wherein the nuclear fuel comprises uranium, a uranium alloy, a uranium compound, plutonium, a plutonium alloy, a plutonium compound, thorium, a thorium alloy, a thorium compound, or a combination thereof.

[0054] Clause 13. A nuclear fuel rod assembly as described in clause 11 or 12, wherein the nuclear fuel comprises uranium nitride.

[0055] Clause 14. A fast reactor nuclear power plant comprising a nuclear fuel assembly according to any one of clauses 11 to 13.

[0056] Clause 15. A method comprising operating a lead fast reactor nuclear power plant at an operating temperature above 600 degrees Celsius utilizing a nuclear fuel assembly according to any one of clauses 11-13.

[0057] Clause 16. A nuclear fuel cladding tube for a liquid metal fast reactor, comprising: a substrate having a tubular shape; and a layer disposed on said substrate, said layer including silicon carbide fibers infiltrated with silicon carbide and configured to inhibit outward creep of said substrate and to inhibit coolant from contacting said substrate.

[0058] Clause 17. A method for preparing a liquid metal fast reactor nuclear fuel rod, comprising depositing a first layer on an exterior surface of a substrate to form a coated substrate, the first layer comprising a corrosion resistant composition, the substrate having a tubular shape, and layering silicon carbide fibers around a form to create a silicon carbide fiber preform. infiltrating the preform with silicon carbide using chemical vapor infiltration, chemical vapor deposition, or a combination thereof to create a second layer having a tubular shape; removing the second layer from the form; and introducing the coated substrate into a cavity defined within the tubular shape of the second layer to form a nuclear fuel rod.

[0059] Clause 18. The method of clause 17, wherein the preform comprises a porosity in the range of 30% to 60% prior to infiltration with silicon carbide.

[0060] Clause 19. The method of clause 17 or 18, further comprising introducing a nuclear fuel comprising uranium nitride into a cavity defined in the substrate.

[0061] Clause 20. The method of clause 17 or 18, wherein the first layer is deposited by physical vapor deposition, cold spray, thermal spray, or a combination thereof.

[0062] Those skilled in the art will recognize that the compositions, articles, methods, and accompanying discussion described herein are used as examples for conceptual clarity, and that various configuration variations are contemplated. Thus, as used herein, the specific examples set forth and the accompanying discussion are intended to be representative of their more general classes. In general, the use of a specific example is intended as representative of its class, and the non-inclusion of specific components (e.g., operations), devices, and objects is not to be considered limiting.

[0063] Various features and characteristics are described herein to provide an understanding of the compositions, structures, manufacture, function, and / or operation of the present invention, including the compositions, coatings, and methods of the present disclosure. It is understood that the various features and characteristics of the present invention described herein may be combined in any suitable manner, regardless of whether such features and characteristics are expressly described in combination herein. The inventors and applicants expressly intend that such combinations of features and characteristics are included within the scope of the invention described herein. Thus, the claims may be amended to recite any features and characteristics expressly or inherently described or otherwise expressly or inherently supported herein, in any combination. Furthermore, the applicants reserve the right to amend the claims to affirmatively disclaim features and characteristics that may exist in the prior art, even if those features and characteristics are not expressly described herein. Any such amendments would therefore not add new matter to the specification or claims, but would comply with the requirements of description, description sufficiency, and additional matter of the specification.

[0064] With respect to the appended claims, those skilled in the art will understand that the operations recited therein may generally be performed in any order. Also, while various operational flows are presented in sequences, it should be understood that various operations may be performed in other orders than those illustrated, or may be performed simultaneously. Examples of such alternative orderings may include overlapping, interleaving, interrupting, reordering, incremental, preparatory, supplementary, simultaneous, reverse, or various other orderings, unless the context dictates otherwise. Moreover, terms such as "responsive to," "related to," or other past tense adjectives are generally not intended to exclude such variations, unless the context dictates otherwise.

[0065] The inventions described herein may comprise, consist of, or consist essentially of various features and characteristics described herein. The terms "comprise" (and any form of comprise such as "comprises" and "comprising"), "have" (and any form of have such as "has" and "having"), "include" (and any form of include such as "includes" and "including"), and "contain" (and any form of contain such as "contains" and "containing") are open-ended linking verbs. Thus, a composition, nuclear fuel assembly, or method that "comprises," "has," "includes," or "contains" a feature and / or characteristic may include, but is not limited to, only possessing that or those features or characteristics, possessing that or those features and / or characteristics. Similarly, elements of a composition, coating, or process that "comprise," "have," "include," or "contain" features and / or characteristics can mean, but are not limited to, possessing only that or those features or characteristics, possessing that or those features and / or characteristics, and may possess additional features and / or characteristics.

[0066] The grammatical articles "a," "an," and "the" as used herein, including the claims, are intended to include "at least one" or "one or more," unless otherwise indicated. Thus, the articles are used herein to refer to one or more (i.e., "at least one") of the grammatical object of the article. As an example, "component" means one or more components, and thus more than one component may be employed or used in the implementation of the compositions, coatings, and processes contemplated and described. Nevertheless, in some instances, the use of the term "at least one" or "one or more" is understood to not result in any interpretation that the failure to use the term limits the referent of the grammatical articles "a," "an," and "the" to only one. Furthermore, unless the context of the usage requires otherwise, the use of a singular noun includes the plural, and the use of a plural noun includes the singular.

[0067] As used herein, unless otherwise indicated, all numerical parameters should be understood to be prefaced and modified in all instances by the term "about," where the numerical parameter accounts for the inherent variability characteristic of the underlying measurement technique used to determine the numerical value of the parameter. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter set forth herein should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0068] Any numerical range recited herein includes all subranges subsumed within the recited range. For example, a range of "1 to 10" includes all subranges between the recited minimum of 1 and the recited maximum of 10 (including the boundaries), i.e., all subranges with a minimum of 1 or more and a maximum of 10 or less. Also, all ranges recited herein include the endpoints of the recited range. For example, a range of "1 to 10" includes the endpoints 1 and 10. Any maximum numerical limit recited herein is intended to include all lower numerical limits subsumed therein, and any minimum numerical limit recited herein is intended to include all higher numerical limits subsumed therein. Accordingly, applicants reserve the right to amend this specification, including the claims, to explicitly recite any subranges subsumed within an expressly recited range. All such ranges are essentially described herein.

[0069] Any patents, publications, or other documents identified herein are incorporated herein by reference in their entirety, unless otherwise indicated, but only to the extent that the incorporated material does not conflict with existing descriptions, definitions, descriptions, illustrations, or other disclosure material expressly set forth herein. Thus, and to the extent necessary, the express disclosure set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portions thereof, that is referred to as being incorporated herein by reference but that conflicts with existing definitions, descriptions, or other disclosure material set forth herein, is incorporated only to the extent that there is no conflict between the incorporated material and the existing disclosure material. Applicant reserves the right to amend this specification to explicitly recite the subject matter or portions thereof incorporated by reference. Amendments to this specification adding such incorporated subject matter will comply with the description, description sufficiency, and additional matter requirements of the specification.

[0070] Although particular embodiments of the present invention have been described above for purposes of illustration, it will be apparent to those skilled in the art that many variations in the details of the invention may be made without departing from the invention as defined in the appended claims.

Claims

1. A fast reactor nuclear fuel cladding tube, A substrate having a tubular shape; a first layer deposited on an exterior surface of the substrate, the first layer comprising an anti-corrosion composition; a second layer deposited on the first layer, the second layer including silicon carbide fibers infiltrated with silicon carbide and configured to inhibit outward creep of the substrate; a gap is defined intermediate the first layer and the second layer; Nuclear fuel cladding.

2. 10. The nuclear fuel cladding tube of claim 1, wherein the silicon carbide fibers are infiltrated with silicon carbide by a liquid preceramic polymer and decomposition of the liquid preceramic polymer into silicon carbide, chemical vapor infiltration, chemical vapor deposition, or combinations thereof.

3. 10. The nuclear fuel cladding tube of claim 1, wherein the corrosion resistant composition comprises titanium, a titanium alloy, aluminum, an aluminum alloy, chromium, a chromium alloy, zirconium, a zirconium alloy, a ceramic, or a combination thereof.

4. The corrosion-resistant composition comprises Ti ２ AlC, TiAlN, Zr ２ 10. The nuclear fuel cladding tube of claim 1 comprising AlC, chromium, chromium nitride, alumina, or combinations thereof.

5. The nuclear fuel cladding tube of claim 1 , wherein the substrate comprises zirconium, a zirconium alloy, iron, an iron alloy, or a combination thereof.

6. The nuclear fuel cladding tube of claim 1 , wherein the substrate comprises a martensitic stainless steel alloy, an austenitic stainless steel alloy, or a nuclear grade zirconium alloy.

7. The nuclear fuel cladding tube of claim 1 , wherein the second layer comprises a porosity in the range of 5% to 30% by volume.

8. The nuclear fuel cladding tube of claim 1 , wherein the first layer comprises a thickness in the range of 0.1 microns to 10 microns.

9. The nuclear fuel cladding tube of claim 1 , wherein the second layer comprises a thickness in the range of 30 microns to 500 microns.

10. 1. A nuclear fuel rod assembly comprising: A nuclear fuel cladding tube according to claim 1; and a nuclear fuel disposed within the nuclear fuel cladding tube.

11. 11. The nuclear fuel rod assembly of claim 10, wherein the nuclear fuel comprises uranium, uranium alloys, uranium compounds, plutonium, plutonium alloys, plutonium compounds, thorium, thorium alloys, thorium compounds, or combinations thereof.

12. 11. The nuclear fuel rod assembly of claim 10, wherein the nuclear fuel comprises uranium nitride.

13. A fast reactor comprising a nuclear fuel assembly according to claim 10.

14. 11. A method comprising operating a lead fast reactor at an operating temperature above 600 degrees Celsius utilizing the nuclear fuel assembly of claim 10.

15. 1. A method for preparing a nuclear fuel rod for a fast reactor, comprising: depositing a first layer on an exterior surface of a substrate to form a coated substrate, the first layer comprising an anti-corrosion composition, the substrate comprising a tubular shape; layering the silicon carbide fibers around a mold to create a silicon carbide fiber preform; infiltrating the preform with silicon carbide using a liquid preceramic polymer and decomposition of the liquid preceramic polymer into silicon carbide, chemical vapor infiltration, chemical vapor deposition, or a combination thereof to create a second layer having a tubular shape; removing the second layer from the form; and and introducing the coated substrate into a cavity defined within the tubular shape of the second layer to form the nuclear fuel rod.

16. The method of claim 15, wherein the preform comprises a porosity in the range of 30% to 60% prior to infiltration with silicon carbide.

17. The method of claim 15 further comprising introducing a nuclear fuel comprising uranium nitride into a cavity defined in the substrate.

18. The method of claim 15 , wherein the first layer is deposited by physical vapor deposition, cold spray, thermal spray, or a combination thereof.

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